Electrosurgical scissors

ABSTRACT

Embodiments are directed to various monopolar and bipolar electrosurgical scissor instruments. A monopolar electrosurgical scissor instrument includes one scissor blade that has an electrically conductive tapered edge, where the tapered edge is insufficiently sharp to shear or otherwise mechanically cut tissue. The scissors also include another electrically insulated scissor blade movably mounted to the first scissor blade. The second scissor blade includes a flat contact surface that is aligned with the tapered edge of the first scissor blade. The scissors further include a scissor body that includes a conductor that transfers electrical energy from an energy source to the tapered edge of the first electrically conductive scissor blade to electrically cut interlaying tissue located between the first electrically conductive scissor blade and the second electrically insulated scissor blade.

BACKGROUND

Historically, tissue has been cut with scissors of various designs by amechanical shearing action as sharpened blades move past each other onclosing. The mechanical limitations of typical scissor designs and thevariation in tissue types result in the following problems andcomplications: tissue squeezing out of the scissor on compression(“popping out”); incomplete cuts; cut edges that are uneven (caused bydull scissors or changes in tissue type); the inability to see/determineexactly what is being cut; separation and jamming of scissor bladeswithout cutting tissue when fibrous, fatty, or tough tissue gets caughtbetween blades; and dulling of the scissors due to limitations ofmaterials and mechanisms. Additionally, the sharp blades of traditionalscissors may inadvertently knick or damage other tissues or structures,such as nerves, blood vessels, tendons, sutures, implanted electricalleads (pacemaker, defibrillator, neural stim, etc.) and surgicalpersonnel. Furthermore, general scissor designs do not provide amechanism to stop bleeding once tissue has been cut.

With the advent of electrosurgery, both monopolar and bipolar scissordesigns have been produced to allow for application of electrical energyto stop bleeding after tissue has been cut with the scissors. Thesedesigns have attempted to combine both the mechanical shearing action ofa regular scissor and the application functionality of electrosurgicalenergy in both cut and coagulation modes. However, attempts toconcentrate electrical energy in a focused manner to enhance the cuttingeffect have been sparse. Indeed, most efforts have been with bipolarinstruments which typically attempt to achieve a small activation zoneeffect through optimal electrode distances and placement.

BRIEF SUMMARY

Embodiments described herein are directed to various monopolar andbipolar electrosurgical scissor instruments. In one embodiment, amonopolar electrosurgical scissor instrument includes one scissor bladethat has an electrically conductive tapered edge that is insufficientlysharp to shear or otherwise mechanically cut tissue. The scissors alsoinclude another electrically insulated scissor blade movably mounted tothe first scissor blade. The second scissor blade includes a contactsurface that is aligned with the tapered edge of the first scissorblade. The contact surface of the second scissor blade may be asubstantially flat edge or a tapered edge. The scissors further includea scissor body that is or has a conductor that selectively transferselectrical energy from an energy source to the tapered edge of the firstelectrically conductive scissor blade to electrically cut interlayingtissue located between the first electrically conductive scissor bladeand the second electrically insulated scissor blade. The scissor bodymay also include a switch for selectively activating the energy sourcethat supplies electrical energy to the scissor. Conversely, the switchmay be located separately from the scissor such as a footswitchactivation mechanism.

In another embodiment, an alternative monopolar electrosurgical scissorinstrument is provided. The scissors include a scissor blade that has anelectrically conductive tapered edge that is insufficiently sharp toshear or otherwise mechanically cut tissue. The scissors also include asecond electrically conductive scissor blade movably mounted to thefirst scissor blade. The second scissor blade includes a contact surfacethat is aligned with the tapered edge of the first scissor blade. Thecontact surface of the second scissor blade may be a substantially flatedge or a tapered edge. The first scissor blade and the second scissorblade are electrically connected to one another. The scissors furtherinclude a scissor body that is or has a conductor that transfers amonopolar output signal from an energy source to the tapered edge of thefirst electrically conductive scissor blade to electrically cutinterlaying tissue located between the first electrically conductivescissor blade and the second electrically conductive scissor blade. Thescissor body may also include a switch for selectively activating theenergy source that supplies electrical energy to the scissor.Conversely, the switch may be located separately from the scissor suchas a footswitch activation mechanism.

In another embodiment, an alternative monopolar electrosurgical scissorinstrument is provided. The scissors include a scissor blade that has anelectrically conductive tapered edge that is insufficiently sharp toshear or otherwise mechanically cut tissue. The scissors also include asecond electrically conductive scissor blade movably mounted to thefirst scissor blade. The second scissor blade includes a contact surfacethat is aligned with the tapered edge of the first scissor blade. Thecontact surface of the second scissor blade may be a substantially flatedge or a tapered edge. The first scissor blade and the second scissorblade are electrically insulated from one another. A minimum clearancespace is provided between the first and second blades to prevent thefirst and second blades from touching. The scissors further include ascissor body that is or has a conductor that transfers a monopolaroutput signal from an energy source to the tapered edge of the firstelectrically conductive scissor blade to electrically cut interlayingtissue located between the first electrically conductive scissor bladeand the second electrically conductive scissor blade. The scissor bodymay also include a switch for selectively activating the energy sourcethat supplies electrical energy to the scissor. Conversely, the switchmay be located separately from the scissor such as a footswitchactivation mechanism.

In another embodiment, an alternative monopolar electrosurgical scissorinstrument is provided. The scissors include a scissor blade that has anelectrically conductive tapered edge that is insufficiently sharp toshear or otherwise mechanically cut tissue. The scissors also include asecond electrically conductive scissor blade movably mounted to thefirst scissor blade. The second scissor blade includes a contact surfacethat is aligned with the tapered edge of the first scissor blade. Thecontact surface of the second scissor blade may be a substantially flatedge or a tapered edge. The first scissor blade and the second scissorblade are electrically insulated from one another. A minimum clearancespace is provided between the first and second blades to prevent thefirst and second blades from touching. The scissors further include ascissor body that is or has two conductors. One conductor selectivelytransfers a monopolar output signal from an energy source to the taperededge of the first electrically conductive scissor blade. The secondconductor acts as a return lead for the monopolar signal andelectrically connects the second electrically conductive scissor bladeto the return input of the ESU. When activated this arrangement servesto electrically cut interlaying tissue located between the firstelectrically conductive scissor blade and the second electricallyconductive scissor blade. The scissor body may also include a switch forselectively activating the energy source that supplies electrical energyto the first scissor blade. Conversely, the switch may be locatedseparately from the scissor such as a footswitch activation mechanism.

In still another embodiment, a bipolar electrosurgical scissorinstrument is provided. The scissors include a scissor blade that has anelectrically conductive tapered edge that is insufficiently sharp toshear or otherwise mechanically cut tissue. The scissors also include asecond electrically conductive scissor blade being movably mounted tothe first electrically conductive scissor blade. The second scissorblade has a contact surface that is aligned with the tapered edge of thefirst scissor blade. The contact surface of the second scissor blade maybe a substantially flat edge or a tapered edge. The scissors alsoinclude a scissor body that is or has conductors that transferelectrical energy from an energy source to the tapered edge of the firstelectrically conductive first scissor blade in a first polarity andtransfers electrical energy to the substantially flat contact surface ofthe second scissor blade in a second polarity that is opposite from thefirst polarity. The transferred energy electrically cuts interlayingtissue located between the first electrically conductive scissor bladeand the second electrically conductive scissor blade. The scissor bodymay also include a switch for selectively activating the energy sourcethat supplies electrical energy to the scissor. Conversely, the switchmay be located separately from the scissor such as a footswitchactivation mechanism.

This Summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used as an aid in determining the scope of the claimed subjectmatter.

Additional features and advantages will be set forth in the descriptionwhich follows, and in part will be apparent to one of ordinary skill inthe art from the description, or may be learned by the practice of theteachings herein. Features and advantages of embodiments of theinvention may be realized and obtained by means of the instruments andcombinations particularly pointed out in the appended claims. Featuresof the embodiments of the present invention will become more fullyapparent from the following description and appended claims, or may belearned by the practice of the invention as set forth hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

To further clarify the above and other advantages and features ofembodiments of the present invention, a more particular description ofembodiments of the present invention will be rendered by reference tothe appended drawings. It is appreciated that these drawings depict onlytypical embodiments of the invention and are therefore not to beconsidered limiting of its scope. The embodiments of the invention willbe described and explained with additional specificity and detailthrough the use of the accompanying drawings in which:

FIG. 1 illustrates a side view of a laparoscopic electrosurgical deviceaccording to one embodiment.

FIG. 2A illustrates an isometric view of an electrosurgical scissorblade with a substantially flat top surface.

FIG. 2B illustrates an isometric view of an electrosurgical scissorblade with a tapered top surface.

FIG. 3 illustrates an isometric view of an electrosurgical scissor bladewith a tapered bottom surface.

FIG. 4A illustrates an isometric view of two electrosurgical scissorblades in which the top blade is powered with electrical energy.

FIG. 4B illustrates an isometric view of two electrosurgical scissorblades in which the bottom blade is powered with electrical energy.

FIG. 4C illustrates an isometric view of two electrosurgical scissorblades in which both the top and bottom blades are powered withelectrical energy, and where the bottom blade has a substantially flattop surface.

FIG. 4D illustrates an isometric view of two electrosurgical scissorblades in which both the top and bottom blades are powered withelectrical energy, and where the bottom blade has a tapered top surface.

FIG. 5 illustrates an isometric view of two electrosurgical scissorblades in a closed position.

FIG. 6 illustrates an isometric view of a biopsy cutter device accordingto one embodiment.

DETAILED DESCRIPTION

Embodiments described herein are directed to various monopolar andbipolar electrosurgical scissor instruments. In one embodiment, amonopolar electrosurgical scissor instrument includes one scissor bladethat has an electrically conductive tapered edge that is insufficientlysharp to shear or otherwise mechanically cut through tissue. Thescissors also include another electrically insulated scissor blademovably mounted to the first scissor blade. The second scissor bladeincludes a contact surface that is aligned with the tapered edge of thefirst scissor blade. The contact surface of the second scissor blade maybe a substantially flat edge or a tapered edge. The scissors furtherinclude a scissor body that is or has a conductor that transferselectrical energy from an energy source to the tapered edge of the firstelectrically conductive scissor blade to electrically cut interlayingtissue located between the first electrically conductive scissor bladeand the second electrically insulated scissor blade. The scissor bodymay also include a switch for selectively activating the energy sourcethat supplies electrical energy to the scissor. Conversely, the switchmay be located separately from the scissor such as a footswitchactivation mechanism.

In another embodiment, an alternative monopolar electrosurgical scissorinstrument is provided. The scissors include a scissor blade that has anelectrically conductive tapered edge that is insufficiently sharp toshear or otherwise mechanically cut through tissue. The scissors alsoinclude a second electrically conductive scissor blade movably mountedto the first scissor blade. The second scissor blade includes a contactsurface that is aligned with the tapered edge of the first scissorblade. The contact surface of the second scissor blade may be asubstantially flat edge or a tapered edge. The first scissor blade andthe second scissor blade are electrically insulated from one another. Aminimum clearance space is provided between the first and second bladesto prevent the first and second blades from touching. The scissorsfurther include a scissor body that is or has a conductor that transfersa monopolar output signal from an energy source to the tapered edge ofthe first electrically conductive scissor blade to electrically cutinterlaying tissue located between the first electrically conductivescissor blade and the second electrically conductive scissor blade. Thescissor body may also include a switch for selectively activating theenergy source that supplies electrical energy to the scissor.Conversely, the switch may be located separately from the scissor suchas a footswitch activation mechanism.

In another embodiment, an alternative monopolar electrosurgical scissorinstrument is provided. The scissors include a scissor blade that has anelectrically conductive tapered edge that is insufficiently sharp toshear or otherwise mechanically cut through tissue. The scissors alsoinclude a second electrically conductive scissor blade movably mountedto the first scissor blade. The second scissor blade includes a contactsurface that is aligned with the tapered edge of the first scissorblade. The contact surface of the second scissor blade may be asubstantially flat edge or a tapered edge. The first scissor blade andthe second scissor blade are electrically insulated from one another. Aminimum clearance space is provided between the first and second bladesto prevent the first and second blades from touching. The scissorsfurther include a scissor body that is or has two conductors. Oneconductor transfers a monopolar output signal from an energy source tothe tapered edge of the first electrically conductive scissor blade. Thesecond conductor acts as a return lead for the monopolar signal andelectrically connects the second electrically conductive scissor bladeto the return input of the ESU. The first conductor selectivelytransfers a monopolar output signal from an energy source to the taperededge of the first electrically conductive scissor blade to electricallycut interlaying tissue located between the first electrically conductivescissor blade and the second electrically conductive scissor blade. Thescissor body may also include a switch for selectively activating theenergy source that supplies electrical energy to the scissor.Conversely, the switch may be located separately from the scissor suchas a footswitch activation mechanism.

In still another embodiment, a bipolar electrosurgical scissorinstrument is provided. The scissors include a scissor blade that has anelectrically conductive tapered edge that is insufficiently sharp toshear or otherwise mechanically cut tissue. The scissors also include asecond electrically conductive scissor blade being movably mounted tothe first electrically conductive scissor blade. The second scissorblade has a contact surface that is aligned with the tapered edge of thefirst scissor blade. The contact surface of the second scissor blade maybe a substantially flat edge or a tapered edge. The scissors alsoinclude a scissor body that is or has a conductor that transferselectrical energy from an energy source to the tapered edge of the firstelectrically conductive first scissor blade in a first polarity andtransfers electrical energy to the substantially flat contact surface ofthe second scissor blade in a second polarity that is opposite from thefirst polarity. The transferred energy electrically cuts interlayingtissue located between the first electrically conductive scissor bladeand the second electrically conductive scissor blade. The scissor bodymay also include a switch for selectively activating the energy sourcethat supplies electrical energy to the scissor. Conversely, the switchmay be located separately from the scissor such as a footswitchactivation mechanism.

Each of the above embodiments will be described with reference to FIGS.1-5 below. FIG. 1 illustrates a laparoscopic electrosurgical device 100that may be used in various laparoscopic or other minimally invasivesurgeries. The laparoscopic electrosurgical device 100 includes variousparts that function together to sever tissue, as directed by theoperator (typically, a surgeon). For instance, the device 100 includes ahandle 101. The handle may be designed such that squeezing the lever ofthe handle toward the other part of the handle activates one or both ofthe electrosurgical scissor blades (105 & 106). This activation maylower the top scissor blade 105 onto the bottom scissor blade 106.Additionally or alternatively, squeezing the lever of the handle mayinitiate the flow of electrical current to one or both of theelectrosurgical scissor blades (105 & 106). In other cases, the handle101 (or another part of the device 100) may include a separate switch orbutton (not shown) that initiates the flow of electrical energy to oneor both of the electrosurgical blades. In still other cases, a switchmechanism such as a foot switch may be used to initiate the flow ofelectrical energy to one or both of the electrosurgical blades.

The handle (or any other part of the laparoscopic electrosurgical device100) may include an input 102 for electrical energy. This electricalenergy may be used to electrically cut any tissue that is between thetop blade 105 and the bottom blade 106. The electrical energy isreceived from a local or remote power source, such as an electrosurgicalgenerator (ESU). The power source may be designed to provide a specifiedamount of electrical energy or current with a specified waveform to oneor both of the electrosurgical scissor blades (105 and/or 106). Theelectrical energy is carried over a wire or other electrical conductorthrough an elongated shaft 104 to the scissor blade(s). In someembodiments, the laparoscopic electrosurgical device 100 may include cap103 that separates the handle 101 and the elongated shaft 104. In someembodiments, the shaft 104 and scissor blades 105/106 of thelaparoscopic electrosurgical device 100 may be inserted into a patient'sbody up to the cap 103. In this manner, the scissor blades can be usedto cut tissue within the patient's body, without having to make a largeincision in the patient's body. As laparoscopic surgical devices aregenerally known in the art, the discussion below will focus on theelectrosurgical blades 105 and 106.

The electrosurgical scissor blades 105 and 106 may be referred to hereinas “energy concentrating scissors”, “energy concentrating scissorblades”, or simply “electrosurgical blades”. Energy concentratingscissors use high density (highly focused) electrical energy to cutthrough tissue after it has been captured in the closed scissors.Because the electrosurgical blades are not sufficiently sharp to shearor otherwise mechanically cut tissue, tissue may be grasped by thescissors without cutting the tissue. The electrosurgical blades willonly cut the tissue when electrical current is applied. As such, adoctor or other user may grasp the tissue between the scissor blades 105and 106 and, after confirming the desired location, positioning, ortissue, may initiate the flow of electricity to one or both scissorblades 105/106. The electrical energy is concentrated along the taperededge 113 (FIG. 3) of the scissor blade 105 and the blade cuts throughthe intervening tissue.

The energy concentrating scissors of the present disclosure presentvarious advantages. For instance, tissue can be firmly grasped orcaptured in the closed electrosurgical scissors without cutting thetissue. When the tissue is firmly grasped by the closed scissors, thetissue may be retracted or pulled away from other bodily structures forviewing prior to electrically cutting the tissue (i.e. activation ofelectrical energy to one or both of the scissor blades). This allows thedoctor or other user to identify tissues and structures that will be cutprior to actually making the cut. The doctor can even pull tissues awayfrom sensitive structures such as nerves, blood vessels, ducts, tendons,etc. to ensure accidental damage does not occur.

The fact that the disclosed electrosurgical scissors do not cut bymechanical shearing provides additional benefits. For instance, since acut is made using electrical energy, there are less compression forcesapplied to the intervening tissue as a cut is made. As a result, theintervening tissue squeezes and “pops out” less during a cuttingprocedure. Additionally, the electrosurgical scissors do not become dulllike mechanical shearing scissors do after repeated use. As such, tissuecuts do not become uneven due to dullness. Moreover, a change in tissuetype does not affect the direction of the cut, which aids in preventinguneven edges.

Furthermore, the electrosurgical scissor blades are not mechanicallysharp enough to cut tissue, structures, etc. Rather, the scissor bladesare designed to only cut tissue that is in contact with a return signalpath (e.g. the return path from blade 105 to blade 106). The surgeon orother user cannot accidentally cut him- or herself or other surgicalpersonnel, or other surrounding nonconductive items such as sutures orgloves. Moreover, since scissor action of the electrosurgical scissorsdoes not include blades moving past each other (e.g., in a mechanicalshearing action), tissue does not get caught between blades and causeseparation and/or jamming of the scissors.

The presently disclosed scissor blades may be coated with an insulatingmaterial. This coating or insulation may cover the entire blade, or maycoat the entire blade with the exception of the concentrating edge 113of the electrosurgical scissors. The insulating material may include oneor more layers of various different materials. Examples of suchmaterials include Polytetrafluoroethylene (PTFE), silicone, other hightemperature polymers, glass, ceramic, other silica based insulatingmaterials, etc. The coating may acts as both a non-stick coating and adielectric layer to help focus energy along the edge of the scissorblade.

Focused electrical energy produces minimal to no thermal necrosis(spread) during activation and cutting. The cut is clean and thermaldamage to adjacent tissue is minimized. The electrosurgical scissors mayuse a relatively low amount of power to generate the cut effect (e.g. inthe range of 20-50 Watts). As such, small structures and thin membranescan be safely cut without damage to neighboring tissue outside theincision line. In some embodiments, coagulation energy may also bedelivered with the active scissor blade to stop bleeding at or near thecut. Vessels may even be grasped and sealed with the application ofcoagulation waveform energy.

The energy concentrating scissors 100 may be implemented insubstantially any scissor style design, including those which currentlyuse a mechanical shearing or cutting action to cut tissue. These stylesmay include, but are not limited to, hand-held scissors such as:straight tipped, curved tip, Iris scissors, Mayo scissors, Metzenbaumscissors, Dura scissors, Braun-Stadler Episiotomy scissors, microscissors, endoscopic scissors and others. It is also applicable tolaparoscopic scissors and other minimally invasive cutting instruments.

In some embodiments, the electrosurgical scissors are designed to havean electric energy concentrating edge 113. This tapered edge may have awidth of about 0.2 mm or less. This allows for a sharpened edge which isnot sharp enough to mechanically cut by itself, but which focuses andconcentrates the electrical energy in a way that easily cuts throughtissue. A coating such as PTFE or other types of fluoropolymers,silicone, other high temperature organic polymers, glass, ceramic,organosilicones and other high temperature combination polymers,diamond, as well as any other high temperature resistant, electricallyinsulative materials may be used to coat or cover the scissor tip(s)108, as well as the whole scissor body or portions of the scissor body105. The edge of the cutting surface 113 may be fully coated, leftuncoated, or cleaned of coating, depending on the insulation value andother coating characteristics of the chosen material in order to focusthe electrical energy. In this way, mechanical shearing is eliminated asthe cutting mechanism, and tissue may be grasped prior to cutting forevaluation and exclusion of tissues or structures that need to beprotected.

FIG. 4A incorporates the elements of FIGS. 2A and 3. As shown in FIG.4A, a monopolar electrosurgical scissor instrument 115 may be provided.The electrosurgical scissors include a top scissor blade 105 that has anelectrically conductive tapered edge 113. As shown by itself in FIG. 3,the top blade 105 has a tapered edge 113 that is insufficiently sharp tomechanically shear or otherwise cut tissue. As explained above, the edge113 may be tapered to a width of about 0.2 mm or less.

The tapered edge 113 of the top scissor blade 105 may also include adropdown rounded corner 112. The dropdown rounded corner 112 allowscontinuous electrosurgical tissue cutting. Accordingly, if electricalenergy is flowing to the top scissor blade 105, the dropdown roundedcorner may slide through tissue, electrically cutting the tissue in acontinuous motion, without requiring the scissor blades to open andclose on the tissue. Like edge 113, however, the dropdown rounded corner112 is not sharp enough to mechanically shear or otherwise cut tissue.Slide cuts are only performed when electrical energy is flowing to thescissor blade 105.

The monopolar scissors 115 also include an electrically insulated bottomscissor blade 106A that is positioned below the top blade 105 and ismovably mounted to the top scissor blade. As shown in FIG. 2A, thebottom scissor blade 106A includes a substantially flat contact surface107A that is aligned with the tapered edge 113 of the top scissor blade105. The bottom scissor blade 106A, like the top blade 105, includes amounting hole 109 through which a mounting pin or other fasteningmechanism may be used to fasten the two scissor blades together. Thescissor blades may separate (as shown in FIG. 4A) to allow the insertionof tissue between the blades. The blades may then be closed as shown inFIG. 5. The bottom scissor blade 106A includes a cavity 110 throughwhich the interlocking portion 111 and/or a portion of the dropdownrounded corner 112 of the top blade 105 is allowed to pass. The cavityand interlocking portion may align the scissor blades to ensure that theblades do not bend or twist in response to pressure applied to thetissue. The cavity 110 may also simply allow at least of portion of thedropdown rounded corner 112 to be inserted therein as the scissors areclosed.

In some cases, as shown in FIG. 2B, the bottom scissor blade 106B mayhave a tapered edge 107B. In such cases, both the top blade 105 and thebottom blade 106B include tapered edges (113 and 107B, respectively). Aswith the top scissor blade's tapered edge 113, the bottom blade'stapered edge 107B is insufficiently sharp to shear or otherwisemechanically cut tissue. The cutting occurs only when electrical energyis applied. The bottom scissor blade, whether tapered (106B) or flat(106A) may be electrically insulated, or may be electrically conductive.Likewise, whether tapered (106B) or flat (106A), the bottom scissorblade may include a cavity 110 for receiving the dropdown rounded corner112 of the top scissor blade 105.

The bottom scissor blade 106 may be toothed to clamp tissue between thetop scissor blade 105 and the bottom scissor blade. The teeth may besubstantially any shape or size, and may be arranged in any of a varietyof different patterns. Additionally or alternatively, the bottom scissorblade may be U-shaped to clamp tissue between the top and bottom blades.The outside edges of the top and bottom scissor blades may be blunted toallow blunt dissections. Thus, the blunt tips 108 may be inserted into abody cavity, and the scissor blades may be used to separate tissues inthe cavity without mechanically or electrically cutting those tissues.

The electrical energy used to perform the cutting in the monopolarelectrosurgical device 115 may include a pulse waveform that varies theamount of current delivered to the scissor blade(s) based on adetermined impedance level of the tissue. Thus, current may be deliveredto the electrically conductive top scissor blade 105 to perform a cut.The current may vary depending on a measured impedance level of thetissue being cut. This impedance level may increase or decrease based onthe amount or type of tissue that is currently between the top andbottom blades (105 and 106). If there is a greater amount of tissue, orif there is a denser type of tissue, more current may be sent to theblade(s). Conversely, if there is a lesser amount of tissue, or if thereis a less dense type of tissue currently between the blades, lesscurrent may be sent to the blade(s) to cut the tissue. A coagulationsignal may also be sent through the top electrically conductive scissorblade 105, the bottom electrically conductive scissor blade 106, or thetop and bottom electrically conductive scissor blades (105 and 106) tocoagulate surrounding tissues. The coagulation signal may thus bedelivered through the active scissor tip(s) to help stop bleeding of cuttissues and vessels. This design may also be employed as a cutting bladefor vessel sealers to cut tissue that has been, or is about to besealed. This may, at least in some embodiments, replace mechanicalcutters often used in commercial vessel sealing products.

The monopolar electrosurgical scissors 115 further include a scissorbody (as shown in the laparoscopic electrosurgical device 100 of FIG. 1)that includes a switch or lever 101 that selectively transferselectrical energy from an energy source to the tapered edge 113 of theelectrically conductive top scissor blade 105. When activated,electrical energy is transferred to the top scissor blade 105 which thencuts interlaying tissue located between the top electrically conductivescissor blade 105 and the bottom electrically insulated scissor blade106A.

In another embodiment, shown in FIG. 4C, an alternative monopolarelectrosurgical scissor instrument is provided. The electrosurgicalscissors include a top scissor blade 105 having an electricallyconductive tapered edge 113. The tapered edge 113 is insufficientlysharp to shear or otherwise mechanically cut tissue. The scissors alsoinclude a bottom electrically conductive scissor blade 106 movablymounted to the first scissor blade 105. The bottom scissor bladeincludes a substantially flat contact surface 107A that is aligned withthe tapered edge 113 of the top scissor blade. Thus, when the topscissor blade is lowered to the flat contact surface 107A, the twoblades meet, as shown in FIG. 5. In some cases, the bottom scissor blade106B may include a tapered edge 107B (as shown in FIG. 2B).

In this embodiment, the top scissor blade 105 and the bottom scissorblade 106 are electrically insulated from one another, and a minimumclearance space is provided between the top and bottom blades to preventthe top and bottom blades from touching when the scissor is closed. Insome cases, the electrosurgical scissors may be designed to allowelectrical current to be returned via an electrically conductive bottomblade. Thus, various embodiments are possible.

As shown in FIG. 4A, shading on the top blade 105 indicates that the topblade is conductive and can allow electrical current to flow through it.FIG. 4B illustrates an embodiment where the top blade 105 is insulatedand the bottom blade 106B (with tapered edge 107B) is conductive (asindicated by the shading). The bottom blade 106B includes a roundedcorner 112 for performing continuous cuts when power is activated. Thetop blade 105 includes a cavity 110 for receiving the aligning member111 of the bottom blade 106B. The top blade may have a flat edge (107A)or a tapered edge (107B) (as shown). FIGS. 4C and 4D illustrate bipolarembodiments where both blades are conductive. FIG. 4C illustrates thecase where the bottom blade 106A has a substantially flat contactsurface 107A, while FIG. 4D illustrates the case where the bottom blade106B has a tapered contact surface 107B.

As with other embodiments described above, the electrosurgical scissors115 of FIG. 4C may include a scissor body (e.g. a laparoscopic body 100)that includes a switch or lever (e.g. handle 101) that selectivelytransfers a monopolar output signal from an energy source to the taperededge 113 of the electrically conductive top scissor blade 105 toelectrically cut interlaying tissue located between the electricallyconductive top scissor blade 105 and the electrically conductive bottomscissor blade 106.

A vessel sealing instrument may be configured to cauterize and trimtissue. The vessel sealer may include a monopolar scissor type bladecutter such as the electrosurgical scissors shown in FIG. 4A. The vesselsealing instrument may also include a monopolar signal with electricalreturn through other contact portions of the sealer, such as thescissors shown in FIG. 4B. As explained above, a minimal clearance isprovided between blades so that the scissor blades do not touch whenclosed. The vessel sealing instrument may further include a bipolarscissor type blade cutter (with the energy concentrating featuresoutlined above), such as the scissors shown in FIG. 4C. Again here, aminimal clearance is provided between scissor blades so the blades donot touch when closed.

Other embodiments for a vessel sealer include using the dropdown curvededge 112 as a sliding cutter. The top blade is activated with electricalenergy (monopolar) and pushed or pulled through the vessel tissuecaptured in a closed sealer clamp before or after sealing is completed.In another embodiment, a vessel sealer may be monopolar and may includea return through other contact portions of the sealer (e.g. via aligningmember 111), and may be pushed or pulled through the vessel tissuecaptured in a closed sealer clamp before or after sealing is completed.Still further, a bipolar vessel sealer may include a sliding cutter(with energy concentrating features) that is activated to performsliding cuts through vessel tissue captured in a closed sealer clampbefore or after sealing is completed. The bipolar vessel sealer mayinclude contact portions for transferring electricity, or may includetwo isolated areas on the scissor blade itself.

In a yet another embodiment, a bipolar electrosurgical scissorinstrument is provided. The scissors include a top scissor blade 105having an electrically conductive tapered edge 113. The tapered edge isinsufficiently sharp to shear or otherwise mechanically cut tissue. Theelectrosurgical scissors also include a bottom electrically conductivescissor blade 106 being movably mounted to the first electricallyconductive scissor blade. The second scissor blade 106A has asubstantially flat contact surface 107A that is aligned with the taperededge 113 of the first scissor blade. The electrically conductive bottomblade 106A may be toothed to clamp tissue between the top scissor blade105 and the bottom scissor blade 106B. The bottom blade may have a flatcontact surface (107A) (as shown in FIG. 4C) or a tapered contactsurface (107B) (as shown in FIG. 4D).

In a bipolar implementation, the electrical energy may include asubstantially continuous waveform supplying substantially continuouselectrical energy to the first and second scissor blades (as opposed tothe variable pulses of the monopolar implementation). As with themonopolar implementation, the bipolar electrosurgical scissors allow asurgeon or other user to close the scissors to clamp the interlayingtissue. The surgeon can then see what tissue is about to be cut. If heor she does not desire to cut, no electrical energy is applied to theblade(s), and the tissue is not cut. If, however, the user does desireto cut, the user pulls a lever or switch to activate the electricalenergy. The scissors then electrically cut the tissue, without shearingit. Because the blades are not sharp enough to shear tissue, the usercannot accidentally nick surrounding tissue or other objects.

In the bipolar implementation, as with the monopolar implementation, theelectrosurgical scissors include a scissor body that has a switch orlever (e.g. handle 101) that selectively activates an electrical energysource so that electrical signal is conducted to the tapered edge 113 ofthe electrically conductive top scissor blade in a first polarity.Conversely, the switch may be located separate from the scissor such asa footswitch activation mechanism. The electrical energy is alsotransferred to the substantially flat contact surface 107A of the bottomscissor blade in a second, different polarity that is opposite from thefirst polarity. The transferred energy electrically cuts interlayingtissue located between the electrically conductive top scissor blade andthe electrically conductive bottom scissor blade (106A). In this manner,the surgeon can grasp the tissue, determine what is being cut, and thenmake the cut. Various different blades may be used, along with differentactive blade scenarios (top blade active, bottom blade active, bothblades active, different sections or traces on one blade active,different sections or traces on both blades active, etc.). The bladesmay also include dropdown curved edges 112 to allow continuous orsliding cuts. The blunt outer edges 108 also allow the scissors to beused for blunt dissections.

Accordingly, monopolar and bipolar electrosurgical scissor embodimentsare described. These electrosurgical scissors may be used toelectrically cut tissue in a variety of different situations, includingin laparoscopic and other minimally invasive surgeries.

Electrosurgical scissor instruments of the present invention may alsotake the form of scissor-type biopsy cutters. Like the embodimentsdiscussed in connection with FIGS. 1-5, the biopsy cutters of thepresent invention may be monopolar or bipolar electrosurgicalinstruments. The biopsy cutters of the present invention may be used tocollect tissue samples for analysis. Incorporation of the principles ofthe present invention into the biopsy cutters enables the biopsy cuttersto cut tissue faster, cleaner, and with less thermal damage to thecollected tissue sample.

FIG. 6 illustrates an exemplary embodiment of a scissor-type biopsycutter 120 that incorporates the principles of the present invention.Biopsy cutter 120 may be connected to the distal end of an elongatedshaft 121. Although not illustrated in FIG. 6, a handle similar tohandle 101 may be disposed at the proximal end of elongated shaft 121 tofacilitate activation of biopsy cutter 120.

Biopsy cutter 120 has a generally clamshell-like configuration. Morespecifically, biopsy cutter 120 includes a first half 122 and a secondhalf 124 connected at a hinge 125. As first half 122 and/or second half124 move about hinge 125, biopsy cutter 120 opens and closes. In otherwords, as first half 122 and/or second half 124 move about hinge 125,first half 122 and second half 124 are moved closer together or furtherapart in a scissor-like action. Thus, biopsy cutter 120 may beconsidered a scissor-type device. Similarly, first half 122 and secondhalf 124 may be considered scissor blades.

As can be seen in FIG. 6, first half 122 includes a cup portion 126 andsecond half 124 includes a cup portion 128. Cup portions 126, 128cooperate to form an interior space within biopsy cutter 120 when firsthalf 122 and second half 124 are closed. When a tissue sample is to beretrieved, biopsy cutter 120 may be opened as shown in FIG. 6 andpositioned so the desired tissue is between first half 122 and secondhalf 124. Biopsy cutter 120 may then be closed so that the desiredtissue is positioned within the interior space formed by cup portions126, 128.

Similar to the scissor instruments described above, electrical currentmay flow from first half 122 and/or second half 124 in order to cut outthe desired tissue sample. As can be seen in FIG. 6, first half 122includes a tapered edge 130 that extends around at least a portion ofcup portion 126. Second half 124 includes a substantially flat contactsurface 132 that extends around at least a portion of cup portion 128and that is aligned with tapered edge 130. Like tapered edge 113described above, tapered edge 130 may have a width of about 0.2 mm orless, which allows for a sharpened edge that is not sharp enough tomechanically cut by itself, but which focuses and concentrates theelectrical energy in a way that easily cuts through tissue.

In a monopolar situation, first half 122 may be conductive such thatelectrical current can flow through it and second half 124 may beelectrically insulated. In a bipolar situation, both first half 122 andsecond half 124 may be conductive.

In alternative embodiments, rather than having a substantially flatcontact surface 132, second half 124 may include a tapered edge similarto tapered edge 130. In such an embodiment, the instrument may beconfigured as a monopolar instrument or a bipolar instrument. Forinstance, in a monopolar situation, either one of first half 122 andsecond half 124 may be conductive while the other is electricallyinsulated. In a bipolar situation, first half 122 and second half 124are both conductive.

Also like the scissors described above in connection with FIGS. 10-5,biopsy cutter 120 may include a coating such as PTFE or other types offluoropolymers, silicone, other high temperature organic polymers,glass, ceramic, organosilicones and other high temperature combinationpolymers, diamond, as well as any other high temperature resistant,electrically insulative materials may be used to coat or cover all orportions of first half 122 and/or second half 124. The edge of taperedsurface 130 may be fully coated, left uncoated, or cleaned of coating,depending on the insulation value and other coating characteristics ofthe chosen material in order to focus the electrical energy. In thisway, mechanical shearing is eliminated as the cutting mechanism, andtissue may be grasped prior to cutting for evaluation and exclusion oftissues or structures that need to be protected.

The present invention may be embodied in other specific forms withoutdeparting from its spirit or essential characteristics. The describedembodiments are to be considered in all respects only as illustrativeand not restrictive. The scope of the invention is, therefore, indicatedby the appended claims rather than by the foregoing description. Allchanges which come within the meaning and range of equivalency of theclaims are to be embraced within their scope.

I claim:
 1. An monopolar electrosurgical scissor instrument, comprising:a first electrically conductive scissor blade comprising (i) a body,(ii) a dropdown corner that is integrally formed with the body and thatextends from the body in a first direction, and (iii) a tapered edgethat is integrally formed with the body and the dropdown corner, thetapered edge extending along the body and onto the dropdown corner in acontinuous manner, the tapered edge being adapted to concentrateelectrical energy transmitted from the electrosurgical scissorinstrument to patient tissue during an electrosurgical procedure, thetapered edge being insufficiently sharp to shear or mechanically cuttissue; a second scissor blade movably mounted to the first scissorblade, the second scissor blade comprising (i) a contact surface that isaligned with the tapered edge of the first scissor blade, and (ii) acavity adapted to receive at least partially therein the dropdowncorner; and a scissor body comprising a conductor that transferselectrical energy from an energy source to the tapered edge of the firstscissor blade to electrically cut interlaying tissue located between thefirst scissor blade and the second scissor blade.
 2. The electrosurgicalscissor instrument of claim 1, wherein the tapered edge on the dropdowncorner is at least partially rounded.
 3. The electrosurgical scissorinstrument of claim 1, wherein the contact surface of the second scissorblade is generally flat.
 4. The electrosurgical scissor instrument ofclaim 1, wherein the body of first scissor blade is coated with amaterial that provides the first scissor blade with electricallyinsulative or non-stick properties.
 5. The electrosurgical scissorinstrument of claim 1, wherein the first direction is in a directiongenerally towards the second scissor blade such that the dropdown cornerextends from the body of the first scissor blade generally towards thesecond scissor blade.
 6. The electrosurgical scissor instrument of claim1, wherein at least a portion of the tapered edge on the dropdown corneris oriented generally perpendicularly to at least a portion of thetapered edge extending along the body.
 7. The electrosurgical scissorinstrument of claim 1, wherein the cavity is formed through the contactsurface on the second scissor blade.
 8. An electrosurgical scissorinstrument, comprising: a first electrically conductive scissor bladehaving a body with a tapered edge integrally formed thereon, the taperededge being adapted to concentrate electrical energy transmitted from theelectrosurgical scissor instrument to patient tissue during anelectrosurgical procedure, the tapered edge being insufficiently sharpto shear or mechanically cut tissue, the first scissor blade also havinga dropdown rounded corner that extends away from the body, wherein thetapered edge extends onto the dropdown rounded corner; a second scissorblade movably mounted to the first scissor blade, the second scissorblade comprising a contact surface that is aligned with the tapered edgeof the first scissor blade and a cavity adapted to receive therein atleast a portion of the dropdown rounded corner; and a scissor bodycomprising a conductor that transfers electrical energy from an energysource to the tapered edge of the first scissor blade to electricallycut interlaying tissue located between the first scissor blade and thesecond scissor blade.
 9. The electrosurgical scissor instrument of claim8, wherein the portion of the tapered edge that extends onto thedropdown rounded corner allows for continuous electrosurgical tissuecutting when the first and second scissor blades are maintained in astationary configuration relative to one another.
 10. Theelectrosurgical scissor instrument of claim 8, wherein the secondscissor blade is electrically insulated.
 11. The electrosurgical scissorinstrument of claim 8, wherein the second scissor blade is electricallyconductive.
 12. The electrosurgical scissor instrument of claim 8,wherein the contact surface of the second scissor blade comprises anelectrically insulated tapered edge that is insufficiently sharp toshear or mechanically cut tissue.
 13. The electrosurgical scissorinstrument of claim 8, wherein the contact surface of the second scissorblade comprises an electrically conductive tapered edge that isinsufficiently sharp to shear or mechanically cut tissue.
 14. Theelectrosurgical scissor instrument of claim 8, wherein the contactsurface of the second scissor blade comprises a substantially flat andelectrically insulated edge.
 15. The electrosurgical scissor instrumentof claim 8, wherein the contact surface of the second scissor bladecomprises a substantially flat and electrically conductive edge.
 16. Theelectrosurgical scissor instrument of claim 8, wherein the tapered edgeof the first scissor blade has a width of about 0.2 mm or less.
 17. Theelectrosurgical scissor instrument of claim 8, wherein the contactsurface of the second scissor blade has a width of about 0.2 mm or less.18. The electrosurgical scissor instrument of claim 8, wherein the firstscissor blade is coated with an electrically insulating material. 19.The electrosurgical scissor instrument of claim 8, wherein, except onthe tapered edge, the first scissor blade is coated with an electricallyinsulating material.
 20. The electrosurgical scissor instrument of claim8, wherein the first scissor blade is coated with a non-stick material.21. The electrosurgical scissor instrument of claim 8, wherein thecavity extends through the contact surface on the second scissor blade.22. The electrosurgical scissor instrument of claim 8, wherein a firstportion of the tapered edge extends in a first direction along a lengthof the first scissor blade and a second portion of the tapered edge,that extends onto the dropdown rounded corner, extends in a seconddirection generally towards the second scissor blade.
 23. Theelectrosurgical scissor instrument of claim 8, wherein the secondscissor blade is at least one of toothed and textured to clamp tissuebetween the first scissor blade and the second scissor blade.
 24. Theelectrosurgical scissor instrument of claim 8, wherein the secondscissor blade is U-shaped to clamp tissue between the first scissorblade and the second scissor blade.
 25. The electrosurgical scissorinstrument of claim 8, wherein the first and second scissor bladescomprise outside edges that are blunted to allow for blunt dissections.26. The electrosurgical scissor instrument of claim 8, wherein theelectrosurgical scissors comprise at least one of the following types ofscissors: straight tipped, curved tip, Iris scissors, Mayo scissors,Metzenbaum scissors, Dura scissors, Braun-Stadler Episiotomy scissors,Micro scissors, endoscopic scissors, and laparoscopic scissors.
 27. Theelectrosurgical scissor instrument of claim 8, further comprising acontroller associated with the first electrically conductive scissorblade, the controller being adapted to generate the electrical energy ina pulse waveform that varies the amount of current delivered to thefirst scissor blade based on a determined impedance level of theinterlaying tissue.
 28. The electrosurgical scissor instrument of claim8, further comprising a controller associated with the firstelectrically conductive scissor blade, the controller being adapted togenerate a coagulation signal that can be sent through the firstelectrically conductive scissor blade to coagulate surrounding tissues.29. The electrosurgical scissor instrument of claim 8, wherein thescissor body further comprises a switch that selectively transferselectrical energy via the conductor from the energy source to thetapered edge of the first scissor blade to electrically cut interlayingtissue located between the first scissor blade and the second scissorblade.